Comparison of flight mechanic propeller driven air planes and birds
Both birds and airplanes have a requirement that they must overcome the force of gravity in order to make flights. Due their weight difference, airplanes and birds differ in power requirement for flying. The power to bring balance between the lift and gravity, drag and thrust such that any flying object can fly comfortably varies as power the weight of these objects. Depending on the power capability of birds and airplanes there are limits for weight requirements for these objects. Airplanes require powerful engines to fly their heavy weight. Most commonly heavy airplanes use jet engines to fly the heavy jets. Birds utilize their hot metabolic blood nature to assist them in propelling their heavy bodies.
The mechanics of birds and airplanes to facilitate flying involves creation lift and thrust. To achieve flying in airplanes the wings provide lift while the propeller generates thrust. In birds, thrust and lift is achieved by flapping of wings. Continuous flapping of wings is use to change shape and deform elastically throughout the wing stroke. Bird’s wings provide dual action for flying as the flapping contributes to both overcoming drag and gravity. Gravity is counteracted by lift whereas drag is managed by thrust or propulsion. In airplanes, propellers are used to derive thrust. Rotating wings and jet engines are used to force air backwards. Jet engines achieve this by generating hot air whose expansion is used to push air backwards as explained by Bernoulli’s effect. It is thus clear that birds counteract both drag and gravity through a dual action of flapping wings whereas in airplanes the effects are achieved separately through propellers and jet engine. Lift is achieved through the movement of the wings of birds or those of the airplanes through the air rather than the air moving over the wings. The air that moves over the trailing end of the wings of birds and planes is directed downwards vertically. The downwards force of the air through the opposite and equal action forces produces the raising effect (lift) of the bird or the plane. The effect applies to both birds and planes.
A description of the forces and mechanisms that provide lift and propulsion in birds
The bird’s powered flight is important control of wing, tail feathers. This assists the birds to overcome gravity, and the air resistance as the birds moves its body upwards. Birds overcome the strong winds, light breezes and changes in the density pressure through the regular adjustments to maintain steady and level flight. Wings maintain the lift force mechanism is a mechanism that birds have to overcome the forces of gravity. Lift is a force that is produced by the action of flow on the wing. The lift force mechanism occurs because the air below the wings has lower pressure as compared above them. This makes birds to overcome the force of gravity and thus birds are now able to fly.
Another mechanism is the mechanism where birds obtain force, which propels them both vertically and forward. This possible because the force used to lift them is generated at an angle of ninety degrees to the flow of air. The wings are modified to in a cross-section, tapering from the leading age to trailing age. Flapping mechanism also, help birds to fly. As bird wings flap this creates a propulsion force which help birds fly as the propulsion force lift the birds. The birds through flapping of their wings dually generate the counteracting forces of both gravity and drag. The presence of ideal fluids which do not have viscosity, this fluid for example traps air making the movement difficult. Absence of the fluid makes the bird and thus able to fly easily.
Hovering is another mechanism which makes birds to fly. The birds that fly have high aspect ratio wings that are adapted to speed flying. Hovering generate lift through flapping of the wing by birds. The flapping mechanism demands less energy because the birds are able to use the force generated by air and thus bird can easily fly. Large birds which hover for long time fly into a headwind, allowing them to remain stationary in relationship to the ground.
The propulsion and thrust are two mechanisms which help birds overcome both drag and gravity forces. The drag is overcome by lift through flapping of wings while drag is overcome by propulsion or thrust. Thrust is generated by wings through flapping which propel the birds upward. When thrust and gravity are overcome the birds are able to fly.
Adaptation of birds to flight
Birds specially use their wings exquisitely to propel their body against the pulling back force known as gravity. As birds or airplanes move up, they face many different forces that include resistance from strongly moving winds as they go into higher attitudes, intensely light breezes that alter the density of the air requiring more force to overcome it. To ensure less energy usage by birds and minimal fuel is combustion by airplanes.
The wings of birds modified at the front in a sharp edged manner to ensure they cut through the dense air with lots of and less energy usage. The feathers have tips at the end and relatively light to give the birds ease of flipping for long distances. This helps the birds fly without quick exhaustion. The wings are very flexible in terms of opening and closing and are longer than the central body. This characteristic helps the bird to easily balance on air, turn on very sharp angles and stop abruptly in case of emergency. The same fact applies on airplanes too. Their streamlined body shapes allow air to pass above in high speeds, which reduces the force of gravity exerted on their bodies. This forms a lift making the force needed to overcome the resistance minimal.
As Bernoulli’s theorem states, a reduction in the cross-sectional area of a tube directly causes an increase in the fluids velocity and a decrease in the pressure they exact. The birds’ legs are modified in a manner that after take-off, they can easily fold inwards to reduce the amount of resistance by blocking the wind. Airplanes also have the same set up of which its landing tires fold out during landing to increase resistance against the air to help in ease of stopping.
Most of the birds have hollow, or their bones are strutted, or we can also refer them to be spongy bones. Most of this bones are pneumatic hence contain air sac which enable most of the birds to have little weight for easy flight and enable them float in the air.
Most of the bones in birds among them including the vertebrae are fused and this provide a rigid
Skeleton that is very important adaptation for flights of the birds.
As another way to reduce weight most of the birds have reduction in some bones. Unlike animals other in birds other bones are difficult to find in birds. These bones that birds lack include lack of teeth, and most of bird species especially the ones that fly do not have the tail bone.
Presences of feathers in all the bird species also help reduce the weight and enable birds to fly. Feathers in birds have more than the function of making the bird light .they also well adapted for insulation of the birds’ body, that is they protect the birds against heat loss and also for most of aerodynamics in birds. This includes the activity that enables the birds to fly in the air.
Other adaptation for flight includes the urogenital adaptations. Some of these adaptations include all the bird species do not have urinary and this makes them to excrete uric acid that enables the birds’ species to conserve water. All the species of birds lay egg. Most of the adult females persists only the left ovary and these help in weight reduction. The sexual Organ in both the sex of birds are enlarged and are only functional during the mating period after which there is always gonads regress. Most of the bird species have endothermic that is they always have very high body temperature that is between 40 to 43 degrees centigrade. Most of the body biochemical process are always very high at high temperature and hence there is rapid and to great extent sustainable production of power for flight.
In birds there digestion is fast and provide and very efficient and from this their body system acquire the power they require to fuel their metabolism. The birds have a very large and well developed breast muscle. Their power down stroke of their wings is more or about to 40% of their total weight of their body. They also have the keeled sternum that enables them to attach their high volume flight muscles. Their heart is chambered enable well circulatory system that nourishes the muscles with blood. They also have a well developed circulatory system that enables the birds to supplied oxygen to muscles.
References:
Sibley, D. (2000). The Sibley guide to birds. New York: Alfred A. Knopf.
Doherty, G., & Reynolds, S. J. (2001). Birds. Tulsa, OK: EDC Pub.
Sachs, A., Julyan, C., MacLeod, A., BBC Scienceworld (Firm), Dorling Kindersley Vision., BBC Worldwide Americas, Inc., & Oregon Public Broadcasting. (2007). Flight. New York, NY?: DK Vision.
Haslam, A., Challoner, J., Barnes, J., & Challoner, J. (2008). Flight. Chicago, IL: World Book in association with Two-Can Pub.
